1. Field of the Invention
The present invention relates generally to a monolithic metallic glass alloy. More specifically, the invention relates to single-phase amorphous alloys having an enhanced ductility, in which the plastic deformation ability thereof is improved, while retaining a single-phase amorphous structure.
2. Description of the Related Art
In general, an amorphous metallic alloy has a high strength (˜2 GPa), an excellent wear and corrosion resistance, and a large elastic elongation (˜2%). Thus, for example, Zr-series amorphous alloys have been applied to sports equipment, high-strength parts or the like.
In particular, a bulk amorphous alloy has an ultrahigh strength and a high strength-to-weight ratio to thereby enable to provide for a high strength lightweight material, and also consists of a uniform microstructure, which thereby leads to a good corrosion and wear resistance.
Therefore, the bulk amorphous alloy technology has a significant influence on various other related technologies and industries, such as unclear atomic energy, aerospace, munitions industry, nano-technology, and the like.
As described above, amorphous metallic alloys have excellent mechanical properties, such as the ultrahigh strength and the broad elastic elongation region. However, in contrast, it does not allow for considerable plastic deformation at ambient or room temperature, thereby resulting in a limitation in their applications.
In order to overcome the above-mentioned limitations, i.e. to solve the poor processing flexibility due to the absence or lack of plastic deformation region, various attempts have been made. For example, elements not related to metallic glass formation are added such that fine precipitates can be formed to thereby provide a composite-like amorphous material.
U.S. Pat. No. 6,623,566 discloses a metallic glass alloy, in which nano particles are dispersed in an amorphous alloy matrix in order to enhance the ductility thereof. U.S. Pat. No. 6,692,590 discloses a method of forming a metallic glass, which consists of an amorphous alloy phase and a quasi-crystalline phase. In U.S. Pat. No. 6,669,793, an amorphous alloy is post-treated so as to form a dendrite phase, thereby enabling to be plastically deformed. In U.S. Pat. No. 6,709,536, a composite of an amorphous and dendrite phase is formed through a chemical treatment, and in U.S. Pat. No. 6,767,419, an amorphous coating is performed and then part of the amorphous coating is transformed into nano-scaled crystalline precipitates.
In these conventional techniques, however, ductile particles are formed in an amorphous matrix to thereby provide a composite-like material, or an amorphous alloy is post-treated so as to have a plastic deformation characteristic. As such, these conventional approaches are not favorable in terms of manufacturing time and cost and consequently in terms of the production efficiency, as compared with a single-phase amorphous alloy form having ductility.
In other words, the aforementioned conventional technique is configured such that ductile particles can be precipitated in an amorphous alloy matrix. Thus, elements unrelated to the amorphous phase formation must be added to form precipitates, thereby forming a composite-like material.